The Pentagon wants to develop a flying car not unlike the one envisioned in the space-age TV show "The Jetsons."

THE GIST

DARPA wants a prototype flying SUV-type vehicle in four years.

The Transformer would enable platoons to land on targets and evacuate quickly if needed.

It should be able to carry four people and 350 pounds up to 250 nautical miles on a tank of gas.

Hoping to bridge the gap between SUVs and helicopters, the military's advanced research projects agency is seeking proposals for flying cars.

The idea is to give troops more flexibility to reach targeted areas -- however remote -- and to be able to hightail it out of untenable situations.

"A future platoon could fly into a specific location and provide direct boots-on-ground seizure of a critical location," the Defense Advanced Research Projects Agency wrote in briefing materials about the project, known as Transformer, or TX. "If they encounter overwhelming enemy forces, casualties or new orders, they can immediately extract to a new location."

DARPA, which hopes to have a prototype in four years, is looking for a four-passenger vehicle which can transform in about a minute from a Humvee-type land rover to an aircraft that can take off and land vertically like a helicopter. The vehicle should be able to drive and/or fly 250 nautical miles on a single tank of gas. In addition to carrying four people (average weight 180 pounds each), the TX should be able to tote 350 pounds of cargo.

None of the passengers need to be pilots. DARPA wants the TX to be able to takeoff and land autonomously. The solicitation, released on April 12, also says the vehicles should be at least as quiet as conventional autos and single-engine helicopters in flying mode.

The military anticipates that the flying vehicle would help ground troops avoid water, difficult terrain and road obstructions, as well as IEDs (improvised explosive devices) and ambushes.

Currently, "the warfighter is either anchored to the ground...and thus vulnerable to ambush, or reliant on helicopters, which are limited in flight speed and availability," DARPA wrote.limited

The agency, which has budgeted $54 million for the program, plans to begin with the award this year of with several 12-month study contracts and technology demonstrations, totaling $9 million. Phase 2 would entail 18 months of design work by up to two firms, costing up to $10 million. The last phase of the program, estimated to cost up to $35 million, would be for the production of a single prototype.

The project has caught the eye of several firms, including Terrafugia of Woburn, Mass., which already has built and tested a prototype vehicle called the Transition, a lightweight sport aircraft with foldable wings that can be driven on roads. The vehicles cost $194,000 and are expected to be in production before the end of next year.

Terrafugia chief operating officer Anna Dietrich said the company has not yet decided whether it is going to bid for the DARPA work. The Transition needs a runway for takeoff and landings, as opposed to the vertical takeoff envisioned for the Transformer, but Dietrich said there are several overlapping technologies that could be applicable to the DARPA vehicle.

"We wouldn't be looking at it as a modification to our current commercial product," Dietrich said. "That is progressing well."